Broke in the rebuilt 468 BBC motor this weekend getting ready for CFW. MSD 6m ignition, msd dist., msd coil. Electric tach hooked to the msd box became erratic and then the motor quit. Started again and went 100 feet, exact sequence happened. Got towed in. Any ideas ? It seemed that the tach goes wild and the seconds later the motor quits. Need to get this figured out before friday, 3 days planned at CFW Fathers Day.